scholarly journals Yes, a non‐random distribution, but why do dragonflies and damselflies not follow latitudinal gradient rules?

2021 ◽  
Author(s):  
Maya Rocha ◽  
Freddy Palacino ◽  
Pilar Rodríguez ◽  
Alex Córdoba-Aguilar
Keyword(s):  
Species Richness ◽  
Community Assembly ◽  
Latitudinal Gradient ◽  
Environmental Filtering ◽  
Phylogenetic Structure ◽  
Latitudinal Diversity Gradient ◽  
Diversity Gradient ◽  
Historical Processes ◽  
Underlying Mechanisms ◽  
Different Origins

1. Latitudinal diversity gradient (LDG) is the increase in species richness towards the equator and is one of the most consistent patterns in biogeography, where current and historical processes contribute to shape the pattern. 2. Despite that LDG patterns have been described for some insects, the underlying mechanisms associated with community assembly and diversification along modern latitudinal diversity gradient pattern remain unknowledge for many groups. 3. Odonata is an old order of insects that originated during the Carboniferous and has diversified through different eras. Here, we defined co-occurrence based on the presence in ecoregions and 1°×1° grid cells of Odonata species in North America NA, to address their species richness, phylogenetic structure, and species diversification rate along the latitudinal gradient. 4. For the whole order, we found the highest species richness at mid-latitudes, while phylogenetic diversity showed a linear positive pattern along the gradient. Our results showed dragonfly assemblages were clustered along all the gradient, suggesting that environmental filtering sorted the assemblages. Whereas damselfly species assemblages were clustered at mid-latitude and overdispersed into both extremes of gradient, probably community assembly is driving by thermal gradients at mid-latitude, by competitive exclusion at south extreme, and by different origins of the biota at the boreal zone. Our results show that apparently most ancestral lineages of Odonata inhabit tropical zones, where diversified and dispersed to the temperate region, although likely also have been diversified into regions of NA, which might be linked with the highest species richness at mid-latitude for both suborders.

scholarly journals Altitude acts as an environmental filter on phylogenetic composition, traits and diversity in bee communities

2012 ◽  
Vol 279 (1746) ◽  
pp. 4447-4456 ◽  
Author(s):  
Bernhard Hoiss ◽  
Jochen Krauss ◽  
Simon G. Potts ◽  
Stuart Roberts ◽  
Ingolf Steffan-Dewenter
Keyword(s):  
Species Richness ◽  
Community Assembly ◽  
Environmental Gradients ◽  
Environmental Filtering ◽  
High Altitudes ◽  
Phylogenetic Structure ◽  
The Alps ◽  
Phylogenetic Composition ◽  
Species Richness And Abundance ◽  
Bee Communities

Knowledge about the phylogeny and ecology of communities along environmental gradients helps to disentangle the role of competition-driven processes and environmental filtering for community assembly. In this study, we evaluated patterns in species richness, phylogenetic structure and life-history traits of bee communities along altitudinal gradients in the Alps, Germany. We found a linear decline in species richness and abundance but increasing phylogenetic clustering in communities with increasing altitude. The proportion of social- and ground-nesting species, as well as mean body size and altitudinal range of bee communities, increased with increasing altitude, whereas the mean geographical distribution decreased. Our results suggest that community assembly at high altitudes is dominated by environmental filtering effects, whereas the relative importance of competition increases at low altitudes. We conclude that inherent phylogenetic and ecological species attributes at high altitudes pose a threat for less competitive alpine specialists with ongoing climate change.

scholarly journals The contribution of global mountains to the latitudinal diversity gradient

2020 ◽  
Author(s):  
Elkin A. Tenorio ◽  
Paola Montoya ◽  
Natalia Norden ◽  
Susana Rodríguez-Buriticá ◽  
Beatriz Salgado-Negret ◽  
...  
Keyword(s):  
Species Richness ◽  
Unit Area ◽  
Species Turnover ◽  
Geographical Information ◽  
Mountain Ranges ◽  
Terrestrial Vertebrates ◽  
Latitudinal Diversity Gradient ◽  
Diversity Gradient ◽  
Diversity Gradients ◽  
Time And Energy

AbstractThe latitudinal diversity gradient (LDG) is widely attributed to be the result of factors such as time, area, and energy. Although these factors explain most of the variation in lowlands, they fail in mountainous systems, which are biodiversity hotspots that may contribute meaningfully to the strength of the pattern following different evolutionary pathways. However, because lowlands cover the largest portion of the total land, they may have overshadowed the contribution of mountains to the LDG, but no study has addressed this issue in previous macroecological analyses. Here, we propose that the LDG shows a stronger trend in mountain ranges due to their high species turnover, in spite of covering less than one third of the Earth’s land. Using the geographical information for ∼22000 species of terrestrial vertebrates, we show that worldwide mountains harbor the 40% of the global diversity, and when taking into account the area effect, we quantified that mountains harbor close to double the species inhabiting lowlands per unit area. Moreover, when we evaluated the LDG after accounting for area size, we found that species richness increased faster towards the Equator and was better predicted by latitude in mountains than in lowlands. Our findings challenge previously well-supported hypotheses that predict that those regions with greater area, time and energy accumulate more species richness, since mountains are geologically younger, exhibit less energy, and cover smaller areas than lowlands. Hence, mountains represent a paradox, which invites to reevaluate hypotheses regarding macroecological and evolutionary processes driving species diversity gradients.

scholarly journals Local-Scale Environmental Filtering Shape Plant Taxonomic and Phylogenetic Diversity in the Isolated Amazonian Tepui (Tepequém Table Mountain)

2021 ◽  
Author(s):  
Prímula Campos ◽  
Carlos Ernesto Schaefer ◽  
Vanessa Pontara ◽  
Márcio Xavier ◽  
José Frutuoso Vale Júnior ◽  
...  
Keyword(s):  
Species Richness ◽  
Soil Properties ◽  
Community Assembly ◽  
Altitudinal Gradient ◽  
Phylogenetic Diversity ◽  
Local Scale ◽  
Environmental Drivers ◽  
Phylogenetic Distance ◽  
Phylogenetic Structure ◽  
Table Mountain

Abstract Understanding how environmental drivers induce changes in plant composition and diversity across evolutionary time can provide important insights into the mechanisms of community assembly. We evaluated how taxonomic and phylogenetic diversity and structure of plant communities change along a local-scale edaphic and topographic gradient in the Tepequém table mountain, Brazilian Amazon. We selected three phytophysiognomies along the altitudinal gradient: Open Rupestrian Grassland, Shrubby Rupestrian Grassland, and Forest. We compared community composition and taxonomic and phylogenetic diversity between phytophysiognomies, and we tested regression linear effect models to investigate the effect of altitude and soil properties on taxonomic and phylogenetic diversity. The highest species richness and phylogenetic diversity were found at lower elevation for Forest. Mean pairwise phylogenetic distance, mean nearest taxon phylogenetic distance, and all standardised phylogenetic metrics were significantly lower in Shrubby Rupestrian Grassland. This phytophysiognomy showed phylogenetic clustering. Forest showed a cluster pattern when only terminal nodes are considered and random dispersion to deep phylogenetic nodes. Open Rupestrian Grassland also showed random phylogenetic structure. The regression analyses showed that species richness and different phylogenetic diversity metrics were explained by altitude and soil properties. However, standardised metrics were not explained by these environmental variables. Comprehensive studies including the role of environmental drivers in plant evolutionary history along the altitudinal gradient are necessary for explaining community assembly patterns and provide additional information for conservation planning.

scholarly journals Consistency in bird community assembly over medium-term along rural-urban gradients in Argentina

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lucas M. Leveau
Keyword(s):  
Species Richness ◽  
Community Assembly ◽  
Rural Areas ◽  
Urban Areas ◽  
Environmental Filtering ◽  
Bird Species ◽  
Bird Community ◽  
Bird Communities ◽  
Assembly Rules ◽  
Urban Habitats

Abstract Background The analysis of bird community assembly rules is fundamental to understand which mechanisms determine the composition of bird species in urban areas. However, the long-term variation of community assembly rules has not been analyzed yet. The objectives of this study are (1) to analyze the variation of community assembly rules along rural-urban gradients of three cities in central Argentina and (2) to compare the patterns of community assembly between two periods separated by 6 years. Bird surveys were performed along transects in urban, suburban, and rural habitats during 2011 and 2017. Departures from null models that took into account differences in species richness (standardized effect size, SES) were calculated for functional and phylogenetic diversities. Results A total of 57 species were recorded. Bird species richness was higher in suburban than in urban and rural habitats. SES of functional diversity increased over the years and was significantly lower in urban habitats than in rural habitats, showing a pattern of functional clustering in the most urbanized areas and functional randomness in rural ones. Phylogenetic diversity was higher in both suburban and urban habitats than rural ones, and the phylogenetic clustering in rural bird assemblages changed to randomness in suburban and urban habitats. Conclusions Bird communities in urban habitats were phylogenetically random and functionally clustered, evidencing environmental filtering by urbanization. In contrast, bird communities in rural areas tended to be phylogenetically clustered, evidencing that certain clades are adapted to rural areas. The processes structuring bird communities along rural-urban gradients were consistent between the 2 years compared.

scholarly journals Functional volumes, niche packing and species richness: biogeographic legacies in the Congo Basin

2020 ◽  
Vol 7 (3) ◽  
pp. 191582 ◽  
Author(s):  
Frederik Van de Perre ◽  
Michael R. Willig ◽  
Steven J. Presley ◽  
Itoka Jean-Claude Mukinzi ◽  
Mbalitini Sylvestre Gambalemoke ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Assembly ◽  
Species Coexistence ◽  
Environmental Filtering ◽  
Biotic Interactions ◽  
Congo Basin ◽  
Climatic Fluctuations ◽  
Fundamental Goal ◽  
Vicariance Event ◽  
Lowland Forests

Understanding the determinants of species coexistence in complex and species-rich communities is a fundamental goal of ecology. Patterns of species coexistence depend on how biotic interactions and environmental filtering act over ecological and evolutionary time scales. Climatic fluctuations in lowland rainforests of the Congo Basin led to the number of vertebrate species being significantly lower in central compared with northern ecoregions of the Basin. We used null models to assess whether climatic variations affected the community assembly of shrews. A consistent limit to functional similarity of species was not related to species richness. Rather, species richness is constrained by environmental factors, and these constraints are stronger in the central lowland forests of the Congo Basin. By constraining species geographic distributions, historical effects of rainforest refugia arising from climatic fluctuations may affect contemporary species composition of local shrew communities. The Congo River represents a vicariance event that led to allopatric speciation of shrews and continues to represent a barrier to dispersal. Ultimately, the historical effects of this barrier have led to differences in the functional volume of shrew communities in northern and central ecoregions. We suggest that the analyses of community assembly can be used to identify Holocene refugia in the Congo Basin.

scholarly journals Evolutionary time best explains the latitudinal diversity gradient of living freshwater fish diversity

2019 ◽  
Author(s):  
Elizabeth Christina Miller ◽  
Cristian Román-Palacios
Keyword(s):  
Species Richness ◽  
Freshwater Fish ◽  
Surface Area ◽  
Explanatory Power ◽  
Additive Models ◽  
Fish Diversity ◽  
Diversification Rates ◽  
Latitudinal Diversity Gradient ◽  
Diversity Gradient ◽  
Basin Surface

AbstractAimThe evolutionary causes of the latitudinal diversity gradient are debated. Hypotheses have ultimately invoked either faster rates of diversification in the tropics, or more time for diversification due to the tropical origins of higher taxa. Here we perform the first test of the diversification rate and time hypotheses in freshwater ray-finned fishes, a group comprising nearly a quarter of all living vertebrates.LocationGlobal.Time period368–0 mya.Major taxa studiedExtant freshwater ray-finned fishes.MethodsUsing a mega-phylogeny of actinopterygian fishes and a global database of occurrence records, we estimated net diversification rates, the number of colonizations and regional colonization times of co-occurring species in freshwater drainage basins. We used Generalized Additive Models to test whether these factors were related to latitude. We then compared the influence of diversification rates, colonization numbers, colonization times and surface area on species richness, and how these factors are related to each other.ResultsWhile both diversification rates and time were related to richness, time had greater explanatory power and was more strongly related to latitude than diversification rates. Other factors (basin surface area, number of colonizations) also helped explain richness but were unrelated to latitude. The world’s most diverse freshwater basins (Amazon, Congo rivers) were dominated by lineages with Mesozoic origins. The temperate groups dominant today arrived near the K-Pg boundary, leaving comparatively less time to build richness. Diversification rates and colonization times were inversely related: recently colonized basins had the fastest rates, while ancient species-rich faunas had slower rates.Main conclusionsWe concluded that time is the lead driver of latitudinal richness disparities in freshwater fish faunas. We suggest that the most likely path to building very high species richness is through diversification over long periods of time, rather than diversifying quickly.

scholarly journals Differentiation of Environmental Conditions Promotes Variation of Two Quercus wutaishanica Community Assembly Patterns

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 43
Author(s):  
Mao Wang ◽  
Jinshi Xu ◽  
Yongfu Chai ◽  
Yaoxin Guo ◽  
Xiao Liu ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Community Assembly ◽  
Local Community ◽  
Environmental Filtering ◽  
Local Environment ◽  
Qinling Mountains ◽  
Forest Communities ◽  
The Loess Plateau ◽  
Ecological Processes ◽  
Phylogenetic Structure

Two contradictory niche-based processes, environmental filtering and competitive exclusion, are important ecological processes in community assembly. Quercus wutaishanica forests are the climax communities in the Qinling Mountains and the Loess Plateau, China. Since these areas are characterized by different climate and evolutionary histories, these forests could be a suitable study system to test the phylogenetic niche conservatism hypothesis. We compared variation in community assembly of two distinct Q. wutaishanica forest communities and analyzed how the variations are formed. Quercus wutaishanica forest communities had significantly different species pool, phylogenetic structure and phylogenetic diversity between the two regions that were driven by inconsistency in environment conditions and evolutionary history at the local scale. Soil ammonium nitrogen, soil water content, and nitrate nitrogen play a major role in phylogenetic beta diversity patterns. The effect of environmental filtering on community assembly was more significant on the Loess Plateau than in the Qinling Mountains. Our study also found that local environment is important in mediating the patterns of phylogenetic structure. These findings provide insights into the mechanisms of local community assembly.

scholarly journals Relative effects of time for speciation and tropical niche conservatism on the latitudinal diversity gradient of phyllostomid bats

2011 ◽  
Vol 278 (1717) ◽  
pp. 2528-2536 ◽  
Author(s):  
Richard D. Stevens
Keyword(s):  
New World ◽  
Latitudinal Gradients ◽  
Future Research ◽  
Niche Conservatism ◽  
Environmental Determinants ◽  
Environmental Characteristics ◽  
Latitudinal Diversity Gradient ◽  
Diversity Gradient ◽  
Historical Processes ◽  
Diversity Gradients

Determinants of contemporary patterns of diversity, particularly those spanning extensive latitudinal gradients, are some of the most intensely debated issues in ecology. Recently, focus has shifted from a contemporary environmental perspective to a historical one in an attempt to better understand the construction of latitudinal gradients. Although the vast majority of research on historical mechanisms has focused on tropical niche conservatism (TNC), other historical scenarios could produce similar latitudinal gradients. Herein, I formalize predictions to distinguish between two such historical processes—namely time for speciation (TFS) and TNC—and test relative support based on diversity gradients of New World bats. TFS and TNC are distinctly spatial and environmental mechanisms, respectively. Nonetheless, because of the way that environmental characteristics vary spatially, these two mechanisms are hard to distinguish. Evidence provided herein suggests that TNC has had a more important effect than TFS in determining diversity gradients of New World bats. Indeed, relative effects of different historical mechanisms, as well as relative effects of historical and contemporary environmental determinants, are probably context-dependent. Future research should move away from attempting to identify the mechanism with primacy and instead attempt to understand the particular contexts in which different mechanisms have greater influence on diversity gradients.

scholarly journals Truncated bimodal latitudinal diversity gradient in early Paleozoic phytoplankton

2021 ◽  
Vol 7 (15) ◽  
pp. eabd6709
Author(s):  
Axelle Zacaï ◽  
Claude Monnet ◽  
Alexandre Pohl ◽  
Grégory Beaugrand ◽  
Gary Mullins ◽  
...  
Keyword(s):  
Species Richness ◽  
Climate Changes ◽  
Sea Surface ◽  
Marine Phytoplankton ◽  
Sampling Effort ◽  
Early Paleozoic ◽  
Latitudinal Diversity Gradient ◽  
Diversity Gradient ◽  
Geological Past

The latitudinal diversity gradient (LDG)—the decline in species richness from the equator to the poles—is classically considered as the most pervasive macroecological pattern on Earth, but the timing of its establishment, its ubiquity in the geological past, and explanatory mechanisms remain uncertain. By combining empirical and modeling approaches, we show that the first representatives of marine phytoplankton exhibited an LDG from the beginning of the Cambrian, when most major phyla appeared. However, this LDG showed a single peak of diversity centered on the Southern Hemisphere, in contrast to the equatorial peak classically observed for most modern taxa. We find that this LDG most likely corresponds to a truncated bimodal gradient, which probably results from an uneven sediment preservation, smaller sampling effort, and/or lower initial diversity in the Northern Hemisphere. Variation of the documented LDG through time resulted primarily from fluctuations in annual sea-surface temperature and long-term climate changes.

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